delegates doesn't pull the __init__ of a class

[muellerzr]

There is currently a bug with tab completion when it comes to classes and delegates. A prime example is Datasets. It's setup as:

@delegates(TfmdLists)
class Datasets(FilteredBase)

When performing a tab-hint to see the possible parameters, we should see both its parameters as well as TfmdLists for the kwargs. Instead we currently see:

Another example is here is the results of doc:

You can see the kwargs were present in the first, dropped in the last but only a part of TfmdLists' parameters were added. For extra clarity I will manually adjust the delegates() to include TfmdLists' __init__, where we can see it working as expected: